One cause of this condition is hypoplasia of a certain nerve that leads to 
One cause of this condition is hypoplasia of a certain nerve that leads to the organ involved. This condition can result from the "open angle" or "closed angle" form of glaucoma or from the clouding of cataracts. Sufferers of this condition possess acuity of 20/200 or worse. For 10 points, identify this medical condition that results in people using white canes, guide dogs, and Braille.
One cause of this condition is hypoplasia of a certain nerve that leads to the organ involved.
{blindness}